204 
Journal of Agricultural Research 
Vol. I, No. 3 
readings being taken at half-minute intervals during that time. Many 
tests were made, using for transfers +15 bouillon cultures 18 hours to 6 
days old. When 3 to 6 day old cultures were used and kept in the water 
bath for 10 minutes at 51 0 , the organism was not killed; nor was it killed 
at 53 0 C. for the same length of time. 
Maximum Temperature. —The maximum temperature for the organ¬ 
ism isolated from sugar beet is 35 0 C., while the maximum temperature 
for the organism from nasturtium is 33 0 to 34 0 C. 
Minimum Temperature. —The minimum temperature is between o° 
and — 1 0 C. When kept at a temperature of — 2 0 to — 5 0 C. for five days 
by means of an ice and salt mixture, the organism remains alive and 
begins to grow after being restored to room temperature. A good growth 
of the organism occurs in both agar and bouillon at 11.5 0 C. A fair 
growth occurs in bouillon at 8° C. 
Optimum Temperature. —The optimum temperature is 27 0 to 28° C. 
relation to light 
The organism is not especially sensitive to sunlight. Thinly sown 
agar poured plates were exposed in bright sunlight at midday in mid¬ 
winter on bags of crushed ice out of doors, half of each plate being cov¬ 
ered with black paper to serve as a check. The test with the organism 
isolated from sugar beet was as follows: 
Fifty minutes exposure did not kill the organism, for colonies appeared 
on the exposed side of these plates in two days, but no colonies appeared 
on those plates exposed 60 minutes. Three different tests were made. 
The organism isolated from nasturtium proved more resistant to sunlight, 
since a few scattered colonies appeared on the agar plates even after an 
exposure of 80 minutes. 
RELATION TO MOISTURE 
The beet organism is killed very readily by drying, even at a moderate 
or low temperature. When drops of a 1-day-old, well-clouded bouillon 
culture are placed on sterile cover glasses and kept in the dark at a tem¬ 
perature of 21 0 to 25 0 C. from four to five hours, growth occurs in bouillon 
tubes into which these covers are dropped. When kept six hours, all 
the organisms are dead. With 3 to 6 day old cultures treated in the 
same way the organism was able to withstand drying from one to three 
days. 
VITALITY IN CULTURE MEDIA 
This organism lives from 10 to 12 months in liquid media, such as beef 
bouillon, sterile milk, and Fermi’s solution, when kept at temperatures 
varying from 11 0 to 20° C. Bouillon cultures may die in four months and 
less when the plugs in the tubes are loose and such rapid evaporation 
occurs that the culture dries down. This usually takes place in the 
